Electronic devices often receive power from a wall outlet, car power outlet, or other such source. For example, a power plug may include two or more prongs that fit into openings in a wall outlet. The prongs of the plug may connect to conductors in a cord that connects to the electronic device. Power may thus be provided from the wall outlet to the electronic device.
Wall outlets may provide different voltages depending on geographical region. For example, in the United States, the power supplied by a wall outlet is 110 Volts AC. In the United Kingdom it is 220 Volts AC.
Often, an electronic device may need to be powered by a DC voltage instead of an AC voltage. Circuitry such as transformers may be used to convert the AC voltage to a DC voltage, which can then be provided to the electronic device. This circuitry can be located in a unit, often referred to as a brick, located either between the plug and the electronic device, or attached as part of the plug.
These plugs may on occasion be kicked, bumped into, or otherwise struck such that they may become damaged. This is perhaps more likely when circuitry such as a power transformer is included in housing attached to the plug, since the housing itself may be struck causing damage to the attached plug. Also, cords attached to the plugs may be pulled such that damage to the plug may result. In such cases, the damage may expose wires or terminals that are carrying the power supplied by the wall outlet.
Having these wires or terminals exposed may cause various problems. For example, a user may try to unplug a damaged plug. In so doing, the user may make contact with the exposed wires or terminals, which may lead to the user being shocked or electrocuted. Also, the exposed wires or terminals may be shorted by a conductive object, thereby leading to large current flows between the wires or terminals. This in turn may lead to fire or other heat related damage to the wall outlet, conductive object, and surrounding area.
Thus, what is needed are circuits, methods, and apparatus that provide protection from exposed wires or terminals when a plug is damaged or destroyed.